Roof construction



Patented June. 12, 1923.

VUNITED sierras` Hman n. Hanns, or snwrcxnny, rminsnvams.

Boor cons'rnUc'rIoN. I

Application tiled Hatch 9, 1922. Serial No. 542,278.

To all whom z't may concern:

Be it known that I, HERBERT E. MARKS, a

citizen of the United States, and a resident of Sewickleypin the countyof Allegheny and State o ennsylvania, have invented a new and usefulImprovement in Roof Con-4 structions, of which the following is aspeciication.

The invention relates to roof structures of the character disclosed inmy Patent No. 1,398,079, or in other words to .roofstructures whichinclude flanged angle members laid upon roof purlins to form a frame,plaster boards or their equivalent supported y the anges of the anglemembers,'and a body of cementitious material. such as gypsum molded uponand bonded to the plaster boards, the plaster boards affording forms orcentering for the cementitious material while being molded.

An ob'ect of the invention is to provide a `roof which may beconstructed of inexpen- .sive materials and easily and cheaply erected,which is fireproof, an efficient heat insulator, and light in weight butnevertheless strong and durable. Alfurther object is to improve the roofstructure 'of my said patent. l

The invention is applicable to roofs for various purposes, whether iiat,slopinlg, hipped or otherwise irregularly shaped. n the accompanyingsheet of drawings it is illustrated in its applicability to a planesection of a roof. Fig.,1.is a vertical section of the preferred formofroof, taken on a 'plane-'transverse to the purlins; Fig.'2 a

vertical section taken at right angles to Fig. 1, the plane of viewbeing indicated by the line II-II, Fig. 1; Fig. 3 a plan view of theroof showing ortions of its several layers removed and lligs. 4 and5sections corresponding to Fig. 1 showing .modifications ofconstruction.

The roof,may be supportedby any suitable rame construction, of which n opart is illustrated except purlins 1, which, as shown, maybe .in theform of channel beams. Obviously the frame and purlins can be of anymaterial, character or design,

depending upon the kind and size of the roof. The purlins, in the caseof a sloping roof, run parallel to the eaves and ridge, as

usual.

Supported on the purlins and running at right angles thereto, andconsequently'runningV from ridge to eave ina sloping roof,

are a plurality of angle lmembers 2, which may takeA the forni of T-barsresting with their base lian es on thepurlin's and suitably-.secured tereto with their legs pro- -jecting upwardly. These T-ba'rs form thebase or frame of the roofstructure proper and are spaced sufficientlyclose Ato each other that the distance between them can be bridged byordinary sizes of plaster boards 3, which are familiar articles ofcommerce, generally composed 0f and generally quite thm, usually aboutthree-eighths of an inch in thickness.- Theplaster oards are supportedwith their side edges resting upon the Vhorizontal flanges 4 of theT-bars 2, as shown in Figs. 2 kand 3,.

psum or the'like and in lieu thereof other plaster board members are soarranged so as to prevent down-'- ward sagging of the unsupported endsof the plaster boards. i

One layer of plaster boards ,3. rests directly upon the flanges 4 of theT-bars 2,I and the joints where adjacent ends of plas-` ter iboards 3meet are overlap ed by other plaster boards. As shown in 3, additionalplaster boards 5 are preferabl arranged in a second layer coextensivewit igs. 1, 2 andy the plaster boards 3, but laid so as to break jointswith the latter. In the form shown in Fig. 4 relatively narrow sectionsof plaster boards 5a overlap the joints between the main plaster boards,whereas in the modiication shown in Fig. 5 the additional plas- -terboard sections 5b underlie such joints.

In all forms the additional plaster boards Yare preferably cemented tothe main layer of plaster boards. This may be done by spreading vbetweenthe surface of the boards a thin layer of the cementitious material ofwhich the-roof slab is formed'. Y

If desired, metal reinforcement may be interposed between the two layersof plaster boards, as shown at 6 in Figs. 1, 2 and 3, the reinforcementbeing light wire lll) mesh which is completely embedded in the layer Iofcementitious material between the upper and lower plaster boards.

he plaster boards 3 and 5, 3 and 5a or 3 and 5b when placed in themanner described, es ecially when cemented together, form a sugcientlyrigid form or centering forthe molding of the roof slab directlythereon, andalso serve as the lower base of the roof slab. The roof slabis formed from suitable cementitious material, preferably gypsum, whichis mixed with the proper proportion of water, and then molded directlyin place, that is, is poured upon the centerin formed by the plasterboards 3 and 5. he composition of this cementitious material rispreferably the same as, or similar to, that of the plaster boards. It issuch that when oured in place it bonds onto the plaster oards, so thatthe latter and the solidified cementitious material forms a continuousunitary ormonolithic slab 7 of such thickness as to overlie to amaterial depth the tops of the T- bars 2. L

The slab is` preferably reinforced by embedding in the cementitiousmaterial suitable metallic reinforcement 8, such as light metallic lath,wire mesh, or the like. To effectively resist the strains in the slab,

y this metallic vreinforcementis held in such position that whenembedded in the solidified Vcementitious slab it will lie near thebottom of the slab at points intermediate the purlins l and near the topof the slab at points above the purlins. `Such positioning ofthemetallic mesh may be secured by providing holes in the upstanding legsofthe T-bars 2, through which heavy wire orsimilar rods may be threadedfrom side to side of the roof to hold the metallic mesh in place. Forinstance, as shown in Figs. l and 3, one set of such wires or rods 9 arethreaded through holes located quite lowA down to hold the reinforcementdown sub'- stantially in contact with the laster boards at pointsintermediate the pur ins, while anotherseries of rods 10 are threadedthrough holes above the purlins near the tops of the vertical legs ofthe T-bars 2 to hold the reinforcement u at points above the purlins.This metal ic mesh reinforcement may consist of continuous stripsextending from the eaves to the ridge of the roof, or, in the case of aflat roof, from edge to edge thereof; or it may be composed of a numserof pieces, the ends of which are overlapped so that when embedded inthecementi'tious material it has the same reinforcing eflect as acontinuous strip. Also, if desired, the edge ortions of thev metallicreinforcement may ibe bent.l upwardly and made to overlap the upperedges of the T- bars'2, as shown at 11, Fig. 3, so as to secure avcontinuous transverse tie. The

panel shows the second layer of plaster l boards lying on top of thelower layer with alternating joints. In the upper panel the slabreinforcement 8 is 4indicated Jas being positioned by the rods 9 and 10extending through the vertical legs 2 of the T-bars. The roof describedis of simple construction, is easy and cheap to erect and is light.Because `the entirev structure, including the plaster boards, forms amonolithic slab which is reinforced for its entire length and width, thestructure is capable of standing a very considerable load. .The slab isreinforced not only by the metallic mesh vdescribed, but also by theT-bars which become thoroughly embedded in and bonded to thecementitious material. Consequently these T-bars-can be of light crosssection and the slab of minimuln thickness. The plaster boards not onlyform the bottom of the slab, but also serve as a centering, so that theusual centering or forms for erecting roofs loo of this kind can beentirely dispensed with,

thus making a great saving in cost of erection. By having' a doublethickness of plaster boards, or at least having the joints of the mainplaster boards overlapped by sections of plaster boards, andparticularly when these are cementedA together, the plaster .boards aregiven such rigidity` that they do not sag under the load of the wetcementitious material when placed on them. If the plaster boards arecemented together and the cement allowed to set before applying thecementitious material, the plaster boards will have sufiicient rigidity,especially when reinforced by the metallic mesh 6, to support workmenand thus dispense with the neces-y sity of having boards on the roof forworkmen to walk on.

The top surface of this roof structure I' prising a frame, a series ofplaster-board.

supporting members carried by said frame, a layer of plaster boardshaving their op positely dissosed sides supported 'by said members, aditional plaster boards overlap ing and strengthening the contiguousendg of saidllayer of plaster boards, and a cementitious bod moulded onthe laster boards and bonde therewithA and t ereb forming a continuousmonolithic roof sla including the fplaster boards.

2. A roof o t prising a frame, a series of plaster-board su portnmembers carried by said frame, a'llayer o plaster boards having theiroppositely dis sed sides sup rted by said members, a ditional plasterards overlapplaster boards and cemented thereto, and a cementitious bodmoulded on the laster boards and bon ed therewith and t ereb forming a-continuous monolithic roof sla including the plaster boards.

3. A roof of the character described com prising a frame, a series ofplaster-board members carried by said frame, plaster boards having theiroppositely disposed sides'supported bosaid members, a second layer ofplaster ards laid upon said first-named layer with joints alternatintherewith, and a cementitious body mou ded u n the plaster boards andbonded therewit thereb formin a continuous monolithic roof s ab incluing the cementitious body and plaster boards.q

4. A roof of the character describedcomprising a frame a series ofplaster-board supportin members carried b said frame, a. ayer o plasterboards havin their oppositely disposed sides. supported b said members,a second layer of plaster ards laid upon and cemented to saidfirst-named layer with joints alternating therewith, a light metallicreenforcement between said layers of plaster boards, and a cementitiousbody mounted u n the upper layer of laster boards an Lbonded therewithztherey y forming a continuous monolithic roof he character describedcom-l lpur ins supported by the upper portions of said angle members,rods intermediate adjacent purlins sup rted by the lower portions'ofsaid ang e-members, metal .reenping the contiguous ends of said layer offorcin fabric extendin over said rstname and below secon -named rods,and a. cementitious body moulded around said fabric'and on the plasterboards and bonded therewith, thereb form n a continuous monolithic roofs ab inclu 1 the laster` boards, cementitious body an metalicreenforcement.

6. A roof of the character described comprising urlins, metallic an lemembers supporte on the purlins an having op- -positely projectinganges, a layer of plaster `boards supported on said flanges, a secondl'ayer of plaster boards laid upon and cemented to first-named layerhavi joints alternating. therewith, a li ht metx 1c re- \enforcementbetween said ayers in plaster boards, rods above the purlins supportedby the upper portions of said an le members rods intermediate adjacentpurlins supported by the lower portions of said angle members, metalreenforcing fabric extending over said first-named and below saidsecondnamed rods, and a cementitious body mould? ed around said fabricsupported by said rods and on the Eiiwml 0. Jorma.

plaster boards and bonded there-

